| 摘要 |
PURPOSE:To obtain a high reliable semiconductor device, by preventing the effect by moving ion, keeping the containing volume of Na, K, Li under 10ppb, under 400ppb and under 500ppb respectively in electrodes of W or Mo or wirings. CONSTITUTION:The reliability of a MOS type IC device is strongly effected by ion type impurities in a gate oxide film. Materials becoming ion type impurities are alkaline metals, and especially Na has large movability even in a low temperature in SiO2 which is a gate oxide film, and remarkably changes the basic property of the MOS. In the meanwhile, since these are easy to catch impulities, for instance, metallic powders which become the source of spatter targets are highly purified, and subsequently alkaline impurities are reduced, an ingot which is made metallic powders being pressed and shaped is solved in a vacuum, and high purity targets are made by Na under 100ppb, by K under 400ppb and by Li under 500ppb. When an electrode and wirings of W or Mo are made using these materials, the device having the same reliability to hitherto poly Si. |
